Garmin GTM 21 FM TMC Traffic Receiver & Garmin External Microphone

I really like the Garmin Zumo 550 that I use on the Harley Davidson Road King Classic and in the Cherokee Jeep, but there has been one thing missing (well two actually) for me, that I have just rectified with the Garmin GTM 21 FM TMC Traffic Receiver and the Garmin External Microphone.

Here is what I think of them:

GTM 21 FM TMC Traffic Receiver

The GTM 21 FM TMC Traffic Receiver provides the main function of a GPS that I have missed with the Garmin Zumo 550, and that is notification of traffic congestion, road works etc.

The GTM 21 FM TMC Traffic Receiver is an FM -band traffic receiver that provides real-time traffic information to compatible Garmon GPS automotive navigational products. Using this data compatible Garmin products can alert the user to local traffic hold ups and displays graphical map symbols for improved awareness.

The cable replaces your existing power source, so in the Jeep it plugs into the cigarette lighter replacing the existing cigarette charger, and on the Road King Classic it plugs into the external cigarette charger that I have fitted, replacing the fixed power source that I have also fitted (which is a bit of a shame but unless I want to buy two units I will have to live with this). The FM receiver then attaches (preferably vertically) to the windshield with two small but effective plastic suction cups.

The version of the GTM 21 FM TMC Traffic Receiver that I bought cost £37 from Amazon and came with a lifetime premium subscription from Trafficmaster for the UK, BUT can also be used in other countries that provide FREE TMC Traffic Services, of which there are 14 including Spain!: UK, Netherlands, Germany, France, Spain, Italy, Austria, Belgium, Czech Republic, Denmark, Finland, Norway, Sweden and Switzerland.

Importantly there is no software to install, in fact the whole thing genuinely is plug and play.

And it works!!! On both the Road King Classic and the Cherokee Jeep it picked up traffic hold ups (traffic jams in the UK) pretty early on and quickly calculated and communicated different routes. The graphics were highly visible and easy to understand which is crucial on the motorbike, and it has a neat colour coded severity indication:

Green = low severity: traffic moving normally
Yellow = medium severity: traffic is a bit congested
Red = high severity: traffic is heavily constipated congested or stopped.

All in all I am very pleased indeed with the GTM 21 FM TMC Traffic Receiver

GTM 21 FM TMC Traffic Receiver

Garmin External Microphone

This simple and relatively cheap ($11.94 from Amazon) microphone plugs into the Microphone socket on the Garmin Mount (both the bike and the car one) and enables hands free operation of a mobile phone, when the mobile phone is connected to the Garmin Zumo 550 via Bluetooth. So once the iPhone has connected to the Garmin Zumo 550 via Bluetooth it is possible to not only use the Garmin Zumo 550 to make a receive telephone calls, but you can also talk hands free.

The microphone comes with a mount that can be stuck to a dry surface, so in our case the rear view mirror in the Jeep, and although you have a cable dangling it works really well. With the microphone mounted between us both Sands and I were able to hold a conversation at the same time, so it picks up your voice pretty well. The quality was fine as well.

On the bike I have the choice of two clamps, and I have found that the smaller one clipped to the helmet strap just under my chin is the best, and I have tended to wrap some sponge around the microphone to try and reduce the impact of the wind. It works, but not great, although I accept that it wasn’t really designed for use on a motorbike, especially a Harley Davidson with its renowned and distinct noise and the open helmet nature of riding. Still it gives an option that allows the iPhone to be stored securely in a pocket rather than mounted on the bike, and that is a big benefit. I only want the option to use the iPhone on the Road King Classic or Fat Boy as an emergency. Not only is it pretty dangerous to talk while riding, you ride a motorbike to get away from the stresses and strains of modern living, not to take them with you!

Garmin External Microphone